php - mysql where条件问题

Question

是否可以像这样使用WHERE；

$no = $_GET['no'];
$query = "SELECT * FROM `numbers` WHERE `myno` - $no = 4";
...

如果没有，我怎样才能像下面的例子那样得到行？

编辑: 更清楚的是，

$today = date("Y-m-d");
 $query = "SELECT * FROM `dates` WHERE date - $today = 7";

我想查找日期字段为 7 天前的行

谢谢

Answer 1

如果字段是日期字段

$query = "SELECT * FROM `numbers` WHERE `myno` = DATE_SUB(`myno`, INTERVAL 7 DAY)"

编辑:或者我更喜欢这个

$query = "SELECT * FROM `numbers` WHERE DATEDIFF(NOW(), `myno`) = 7"

Take a look at the date functions